Essentials Exam 1

• The semilunar valves are aortic and pulmonic valves
• An anatomic structure found only in the right ventricle is moderator band
• The left atrium receives how many pulmonary veins? four
• Which coronary artery gives rise to the posterior descending artery? both circumflex and right coronary
• The coronary sinus returns blood to the left atrium. False
• Coronary Arteries: Arteries that supply blood to cardiac muscle.
• myocardium: Layer of the heart wall containing cardiac muscle.
• Endocardium: Lines the heart chambers
• Ventricles: Two heart pumps; lower heart chambers
• Atria: Thin walled, superior heart chambers
• Epicardium: Another name for the visceral pericardium.
• Papillary muscles: Enlarged muscles in ventricles attached to chordae tendinae.
• Chordae Tendinae: String like structures attacted to atriovetricular valve leaflets.
• Ligmentum Arteriosum: Remnant of a fetal vessel that closed at birth
• Trabeculae Carnae: Irregularly-shaped muscle bridges found in the ventricles
• Anterior: Describes the front or direction toward the front of the body
• Posterior: Describes the back or direction toward the back of the body.
• Medial: Describes the middle or direction toward the middle of the body.
• Lateral: Describes the side or direction toward the side of the body.
• Proximal: Describes a position in a limb that is nearer to the point of attachment or the trunk of the body.
• Distal: Describes a position in a limb that is farther from the point of attachment or the trunk of the body.
• Superior: Describes a position above or higher than another part of the body proper.
• Inferior: Describes a position below or lower than another part of the body proper.
• Deep: Describes a position farther from the surface of the body.
• Superficial: Describes a position closer to the surface of the body.
• The intercalated disk is a distinct characteristic of cardiac muscle tissue and are attached to myocytes.
• Each myocardial cell contains numerous myofibrils, which are long chains of individual sacromeres, the fundamental contracile units of the cell.
• The mature myocardial cell, a myocyte, measures up to 25 μm in diameter and 100 μm in length.
• The myocyte is the functional cell of the heart.
• As the electrical impulse reaches the AV node, a delay in conduction is encountered (0.1 seconds). This delay occurs because the small diameter fibers in this region conduct slowly, and the action potential is of the slow pacemaker type. This occurs within the AV node fibers and in special junction fibers that connect the node with ordinary atrial fibers.
• The sacromere is composed of alternating thin (actin) and thick (myosin) myofilaments (proteins). Titin is a protein that tethers myosin to the Z-line and provides elasticity.
• The depolarization of the ventricles through both phases of repolarization to the end of the T Wave
• The electrical impulse starts on the sinoatrial (SA) node in the right atrium right at the connection to the superior vena cava.
• The impulse goes through the ventricular muscle at 0.3 - 0.5 meters per second, resulting in a contraction of the ventricles that proceed upward from the apex of the heart toward the base.
• Phase 1: atrial contraction
• Phase 2: IVCT - Isovolmetric Ventricular Contraction
• Phase 3: Rapid Ejection
• Phase 4: Reduced Ejection
• Phase 5: IVRT - Isovolumetric Ventricular Relaxation
• Phase 6: Rapid Filling